Vega-Franco L, Mejía A M, Robles B, Moreno L, Pérez Y
Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional Autónoma de México.
Bol Med Hosp Infant Mex. 1991 Nov;48(11):826-31.
This study gave us the opportunity to know the roles iron deficiency and the presence of lead in blood play, as confounding variables, in relation to the state of malnutrition and the intellect of those children. A sample of 169 school children were classified according to their state of nutrition, their condition in reference to serum iron and lead concentrations. In addition, their intelligence was evaluated. The results confirmed that those children with lower weights and heights registered lesser points of intelligence; in fact, iron deficiency cancels out the difference in favor of those taller and weighing more. Lead did not contribute as a confounding variable, but more than half of the children showed possible toxic levels of this metal.
这项研究让我们有机会了解缺铁和血液中铅的存在作为混杂变量，与那些儿童的营养不良状况和智力之间的关系。169名学童样本根据他们的营养状况、血清铁和铅浓度情况进行了分类。此外，还评估了他们的智力。结果证实，体重和身高较低的儿童智力得分较低；事实上，缺铁消除了有利于那些较高和较重儿童的差异。铅并未作为混杂变量起作用，但超过半数的儿童显示出这种金属可能的中毒水平。
